The Queen will wear a blue hat and Princess Eugenie will be dressed in Erdem and have her first child next year, if the bookmakers’ favourite odds for the royal wedding come true.

Ladbrokes are predicting Erdem, a go-to choice for Eugenie in the past, will be the designer behind the princess’s bridal gown, with odds of 7/2.

Royal Ascot – Day Three – Ascot RacecoursePrincess Eugenie in Erdem at Royal Ascot (Nigel French/PA)

The Queen’s granddaughter has already revealed she has chosen a British-based designer.

Suzannah, founded by Suzannah Crabb and known for creating outfits with vintage charm and a modern edge, is also seen as a possibility at 5/1.

Other suggestions include Jenny Packham at 6/1, London-based duo Preen at 8/1, celebrity bridal favourite Suzanne Neville at 10/1, and Alice Temperley, loved by ethereal boho-brides, also at 10/1.

Ralph & Russo, who made the gown for the Duchess of Sussex’s official engagement photo, are 14/1.

The odds that Eugenie has actually picked French fashion house Givenchy, who crafted Meghan’s elegant pure white wedding gown, are 20/1.

Punters can also get odds of 25/1 that Eugenie has asked couturier Lindka Cierach, who made the royal wedding dress for her mother Sarah, Duchess of York in 1986.

Alex Apati of Ladbrokes said: “Eugenie is no stranger to Erdem and the odds suggest they’ll be her dress designer of choice.”

The colour of the Queen’s hat always generates a flurry of bets, blue is the favourite at 2/1, followed by pink 3/1, orange 4/1, purple 5/1, and green or yellow at 6/1.

Bets on for Queen’s Royal Wedding hatBets on the Queen’s hat for the royal wedding at Ladbrokes are 2/1 for a blue hat, 3/1 for pink, 5/1 for purple and 6/1 for yellow (PA)

The spokesman added: “Plenty of punters cashed in on the Queen’s last hat but we reckon she’ll go back to blue this time out and have cut the odds accordingly.”

The newlywed couple are also predicted to be welcoming their first child soon, with odds that Eugenie will give birth in 2019 set at 3/1, followed by 7/4 for 2020, 4/1 for 2021 and 5/1 for 2022 and beyond.

Charlie van Straubenzee and Daisy Jenks weddingPrincess Eugenie and her fiance Jack Brooksbank at a friend’s wedding (Joe Giddens/PA)

Apati added: “Harry and Meghan look likely to add to the Royal Family in the next 12 months but Eugenie won’t be far behind if the latest betting is anything to go by.”